Recently, a function of controlling a position of an imaging lens with high precision at a high speed by detecting the position of an imaging lens and feeding back the position information has been increasingly introduced into a camera module mounted in a smartphone or the like. In particular, since it is now possible to perform highly-precise hand blur correction by introducing feedback control into optical hand blur correction (optical image stabilization (OIS)), it is expected that more cameras using OIS will be used in the future with the growing demand for capturing distant subjects in a dark place without blurring. In a camera with the OIS function into which such feedback control is introduced, the hand blur is corrected by detecting an angular velocity of the hand blur by a gyro sensor, integrating the detected angular velocity to calculate an angle blur amount, and moving a position of a lens according to the angle blur amount while detecting the position of the lens.
As described above, since the angle blur amount is obtained by integrating the angular velocity, there may be a concern that DC components generated by the integration are accumulated. That is, the DC components are accumulated while repeating the AC operation of hand blur correction. Therefore, when the DC components are accumulated, since the feedback control is performed, the position of the lens is offset, which may make it difficult to give a sufficient displacement to a biased side.
In the related art, a technique has been used in which, when the hand blur correction exceeds a limited range during an operation of OIS, a centering operation is performed and a lens is returned to a predetermined position. The centering operation has been used at the end of divided exposure when optical hand blur correction and addition-type hand blur correction are combined.
When the accumulated DC component of the angle blur signal is refreshed to return to a zero level, the position detection signal of the lens also returns to an initial state and a centering operation is executed. This means that the position of the lens moves suddenly, so that a user may feel a sense of incompatibility due to a sudden image change such as capturing a continuous moving image. If the centering operation is performed so slowly that the user does not feel the sense of incompatibility, there may be a possibility that a movable range becomes insufficient while performing the centering operation, which may result in failure of the hand blur correction.
In the case of performing addition-type divided exposure while executing the optical hand blur correction, when the position of the lens approaches the limit of the movable range, if the divided exposure is terminated and the centering operation is performed, it takes a time to calculate a pixel shift amount for position alignment by comparing images before and after the centering.